This invention relates to a body cavity drain tube used for drainage purposes. In particular, a ventricular tube is discussed, but it should be noted that this invention is not limited thereto. The drain tube of this invention is used as a head for a ventricular tube, and is particularly suitable for removing cerebrospinal fluid from a ventricle.
A ventricular tube, a catheter, having many sidewall holes in its head part and used for the above-mentioned purpose is well known, but these sidewall holes are often blocked by choroid plexus which penetrate into the ventricular tube through the holes. In order to prevent this blockage, various devices have been proposed. For example, a catheter having a curved head part (Japanese Patent Publication No. 44-18711) and a catheter having a head part with many fins protruding vertically with respect to the tube axis (Japanese Laid Open Application No. 48-18711) have been devised.
However, the effect of preventing the blockage of a ventricular tube is still small even with these devices. That is, even with the above-mentioned modified catheters, it is impossible to completely prevent choroid plexus from penetrating into the inside of the catheter through its sidewall holes. Once the choroid plexus penetrates into the inside of the catheter through the sidewall holes in the lowest part of the catheter, the catheter is rapidly blocked and the draining function is completely inhibited, even if the other holes remain open. Thus, the development of a ventricular tube capable of providing a stable and constant drain function has been required.